 <table width="100%" > 
    <tr>
        <td valign="" height="">
            <a  onmouseover="MM_nbGroup('over','BRosaS','images/Boton/BRosaoverT_Salir.png','',1);" onmouseout="MM_nbGroup('out');" onclick="CerrarSesion();">
                <img alt="BRF" title="Cerrar Sesi&oacute;n"  id="BRosaS"  src="images/Boton/BRosaT_Salir.png" />
            </a>
        </td>
    </tr>

    </div>  
</table>